Spanish police have arrested the Ukrainian mastermind of the Carbanak and Cobalt malware attacks which targeted over 1000 financial institutions worldwide, reports Finextra. The crime ring heads has been in operation since 2013 and has resulted in total losses of over €1 billion for the financial industry. The Cobalt malware alone allowed them to steal up to €10 million in each heist, was installed using spear phishing emails containing malicious attachments, and allowed the hackers to remotely control ATMs. Spanish police described the mastermind, identified only as "Denis K", as a computer genius. Twitter has joined Google and Facebook in banning adverts for certain cryptocurrency services and initial coin offering, reports the FT. There will be a global ban on advertising for ICOs (a crowdfunding mechanism using digital currencies). The only cryptocurrency exchanges and online wallet services allowed to advertise on Twitter will be those that are listed publicly on selected major stock markets.